1. Field of the Invention
Sensors with related hardware, pneumatic and electric control circuits are used with machine tools in order to detect the breakage or absence of a tool, the presence and/or absence of a portion of a workpiece and/or other improper conditions which might result in the production of imperfect work, have been employed to prevent the normal operation of the machine whenever such conditions exist.
2. Description of the Prior Art
Illustrative of the prior art is my U.S. Pat. No. 4,056,329 dated Nov. 1, 1977 and entitled "Detection System for Machine Tools" and U.S. Pat. No. 3,647,998 dated Mar. 7, 1972 and entitled "Broken Tool Detector."